Jens Alex

Jens Alex
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Jens verified their affiliation via an institutional email.
Verified
Jens verified their affiliation via an institutional email.
Institut für Automation und Kommunikation · Water and Energy

Dr.-Ing.

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136
Publications
40,921
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2,515
Citations

Publications

Publications (136)
Article
This study extends a previously developed competitive modeling approach for predicting the adsorption of organic micropollutants (OMPs) on powdered activated carbon (PAC) in full-scale advanced wastewater treatment. The approach incorporates adsorption analysis for organic matter fractionation, assumes pseudo-first order kinetics and differentiates...
Article
This paper presents a comprehensive simulation environment for damage analysis of drinking water and sewer systems. Given the potential damage caused by natural disasters or infrastructural problems, analyzing the resilience of such systems is of crucial importance. The presented simulation environment integrates various specialized solvers that ar...
Article
State-of-the-art modelling tools and dynamic simulations have become important tools for planning and operational decision making in the environmental sector, including wastewater treatment plants. Due to increasing regulatory requirements (energy savings, treatment performance , GHG footprint), the practical application of these instruments is bec...
Conference Paper
Highlights  A scalable procedure for automatic simplification of hydrodynamic sewer models is presented  It also covers looped and very large networks, is fast and, thus, is applicable to practice  Topological maps assist in the understanding of the system.  Simplified models are useful for long-term evaluations in large search spaces (e.g. SUD...
Article
Full-text available
The quality of simulations for wastewater treatment plants is heavily dependent on the quality of the simulation input data. Inflow data from wastewater treatment plants collected by measurement cannot usually be used directly for a wastewater treatment plant simulation. A method is presented with which dynamic inflow descriptions for simulation st...
Article
Die modellbasierte Steuerung (Englisch: Model Based Predictive Control - MBPC) verwendet ein internes Simulationsmodell (digitaler Zwilling) des zu steuernden Systems, um das zukünftige Verhalten zu simulieren. MBPC formulieren ein optimales Steuerungsergebnis (Qualitätsfunktion) und verwenden einen mathematischen Optimierungsalgorithmus zur Berech...
Conference Paper
A Digital Twin platform, developed within the "Zwille" research project in Germany, is presented, which supports a wide range of urban water management tasks of a wastewater utility. Fundamental concepts, such as model integration issues, addressing different use cases by different levels of complexity, issues related to model setup and application...
Conference Paper
Die Steuerung des Abflusses erweist sich in vielen Kanalnetzen als ein wirksames Verfahren zur Verringerung von Mischwasserentlastungen und damit zur Verbesserung der Wasserqualität der Vorflutgewässer. Einen Handlungsrahmen für dieses bewusste Eingreifen in die Abflussvorgänge bietet das Merkblatt DWA-M180 sowie der zugehörige DWA-Themenband. Für...
Article
Presenting the methods for Real-time control of urban drainage systems and elaborating in detail on application of model-based predictive control for this task. Novel implementation for developing and simulating model-based predictive control of wastewater systems in a user-friendly simulation system, which is widely applied by practitioners
Article
Schütze, M., Alex, J. (2022): Der Wasserkreislauf als gesamthaftes System – auch in der Modellierung; gwf-Wasser/Abwasser, 5, 2022, 28-31
Article
This work presents a mathematical method to describe adsorptive removal of organic micropollutants (OMPs) and dissolved organic carbon (DOC) from wastewater treatment plant effluent using powdered activated carbon (PAC). The developed model is based on the tracer model (TRM) as a modification of the ideal adsorbed solution theory (IAST) and uses th...
Conference Paper
Full-text available
Highlights • Different subsystems of urban water systems usually use different mathematical solvers (e.g. EPANET, SWMM, WWTP modelling). • A novel modelling approach combines these solvers in a single modelling framework • Integrated modelling of urban water systems becomes more use-friendly and more efficient.
Chapter
Inhalt Vorwort . . . . . . .1 Fertigungsautomation – Digitaler Zwilling: Vom Konzept zur Anwendung Anwendungsfälle und Ansatz zur Erstellung des Digitalen Zwillings aus Sicht eines Komponentenherstellers . . . . . . 5 Interaktion zwischen Steuerungen auf der Basis von OPC UA FX und deren Konfiguration durch Verwaltungsschalen . . . . . . . . . . 19...
Conference Paper
Highlights • A new method/tool to design, simulate and test MPC for RTC of sewer systems is presented. • Existing models can be conveniently implemented as internal models for MPC. • All types of RTC can now be simulated and evaluated in the same simulation environment.
Conference Paper
Full-text available
Highlights • A new method/tool to design, simulate and test MPC for RTC of sewer systems is presented. • Existing models can be conveniently implemented as internal models for MPC. • All types of RTC can now be simulated and evaluated in the same simulation environment.
Article
Zusammenfassung Simulationsmodelle in Form nichtlinearer Prozessmodelle können in vielfältiger Weise für die modellgestützte Betriebsführung eingesetzt werden. In diesem Beitrag werden ein Entwicklungssystem und ein Laufzeitsystem für Beobachter- und Prognosemodelle, modellbasierte prädiktive Regelungen und eine virtuelle Inbetriebnahme vorgestellt...
Experiment Findings
https://www.ifak.eu/de/produkte/sampsons
Article
In Germany, the EU and worldwide, the demands placed on wastewater treatment plants in terms of energy efficiency, cleaning performance, operational reliability and minimization of operating costs continue to grow. This results in an increasing demand for automation solutions with high quality requirements that are well integrated with process engi...
Article
Full-text available
New and alternative sanitation systems are increasingly discussed and find their way into implementation. However, discussions on sanitation concepts often are held in a rather emotional way. Furthermore, not all the available sanitation concepts might be known to the decision maker. The work presented here attempts to contribute to a good discussi...
Article
Ammonia-based aeration control (ABAC) is a cascade control concept for controlling total ammonia nitrogen (NHx-N) in the activated sludge process. Its main goals are to tailor the aeration intensity to the NHx-N loading and to maintain consistent nitrification, to meet effluent limits but minimize energy consumption. One limitation to ABAC is that...
Article
Full-text available
Investigation of various phenomena occurring in sewer systems is critical for increasing the sustainability of such systems. Such investigations also includes gross solids (GS) transport. GS transport may be affected by reduction of flows resulting from population decrease and/or reduced domestic water consumption. The present paper reports on the...
Conference Paper
Full-text available
New Alternative Sanitation Systems (NASS) are based on the paradigm change of turning end-of-pipe systems into resource-oriented sanitation systems. Often, they represent small and decentralised wastewater systems. The introduction of NASS leads to several consequences: NASS introduce a broad variety of additional system options. Decision processes...
Chapter
Inhalt (Auszüge…) Fertigungsautomation – Plant Lifecycle Management Multidimensionale Datenmodellierung und Analyse zur Qualitätssicherung in der Fertigungsautomatisierung . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 B. Lindemann, N. Jazdi, M. Weyrich, Institut für Automatisierungstechnik und Softwar...
Conference Paper
Wastewater infrastructures are long-lived assets. Accordingly, they have to be adapted to evolving challenges and changing conditions in the course of their lifetime. The last years, especially, suggest that urban wastewater systems (UWWS) have to function under different conditions than the ones they were originally built for, up to 150 years ago....
Article
Full-text available
Beim Aufgreifen der Konzepte von Industrie 4.0 für die Abwasserwirtschaft kommt der Vernetzung eine besondere Bedeutung zu. Diese Vernetzung umfasst neben der Technik ebenso Aspekte der Organisation. Der systematische Entwurf von Regelungen ist ein Beispiel dafür, wie wichtig ein Gewerke übergreifender Entwurfsprozess für vollumfänglich funktionier...
Article
Together with significant water savings that onsite greywater reuse (GWR) may provide, it may also affect the performance of urban sewer systems and wastewater treatment plants (WWTPs). In order to examine these effects, an integrated stochastic simulation system for GWR in urban areas was developed. The model includes stochastic generators of dome...
Article
During the design of a water resource recovery facility, it is becoming industry practice to use simulation software to assist with process design. Aeration is one of the key components of the activated sludge process, and is one of the most important aspects of modelling wastewater treatment systems. However, aeration systems are typically not mod...
Conference Paper
During the design of a water resource recovery facility (WRRF), it is becoming industry practice for process engineers to use simulation software to assist with the design of the plant and its aeration system. The aeration process is one of the key components of the activated sludge process, and as such, is one of the most important aspects of mode...
Conference Paper
Full-text available
A new model-based methanol dosage controller for multi-stage Water Resource Recovery Facilities (WRRF) is presented and compared with classic control approaches. The new controller uses self-tuning observer models to predict the concentration of methanol consuming organisms (methylotrophs) and subsequently the remaining methanol concentration in th...
Article
Zusammenfassung In diesem Beitrag wird eine neue Simulationsplattform für Abwassersysteme und insbesondere Kläranlagen vorgestellt, mit der neben der verfahrenstechnischen Funktion vor allem Betriebsführungskonzepte und Steuerungs- und Regelungsvarianten untersucht werden können. Besonderes Augenmerk bei der Entwicklung des Simulationssystems lag a...
Article
This paper describes an integrated approach for designing, testing and implementing process control solutions for Water Resource Recovery Facilities (WRRFs) using a novel simulation platform. The user-friendly modeling and simulation environment encapsulates expert knowledge and standardizes typical tasks and goes far beyond classic simulators in t...
Article
During the design of a water resource recovery facility (WRRF), it is becoming industry practice for process engineers to use simulation software to assist with the design of the plant and its aeration system. The aeration process is one of the key components of the activated sludge process, and as such, is one of the most important aspects of mode...
Article
A new model-based methanol dosage controller for multi-stage Water Resource Recovery Facilities (WRRF) is presented and compared with classic control approaches. The new controller uses self-tuning observer models to predict the concentration of methanol consuming organisms (methylotrophs) and subsequently the remaining methanol concentration in th...
Article
Full-text available
As the work of the IWA Task Group on Benchmarking of Control Strategies for wastewater treatment plants (WWTPs) is coming to an end, it is essential to disseminate the knowledge gained. For this reason, all authors of the IWA Scientific and Technical Report on benchmarking have come together to provide their insights, highlighting areas where knowl...
Presentation
Full-text available
presentation slides from a talk given by Lina Belia at a WEF 100 years of activated sludge conference
Article
Both biofilm processes and the activated sludge process are currently the most common techniques in biological wastewater treatment. In the communal sector the activated sludge process became widely accepted so far. Nevertheless the biofilm processes have some clear advantages in comparison with the activated sludge process, especially with regard...
Article
A sequencing batch reactor (SBR) model was developed consisting of six continuous stirred tank reactors which describe the hydraulic flow patterns occurring in different SBR phases. The model was developed using the results of computational fluid dynamics (CFD) simulation studies of an SBR reactor under a selection of dynamic operational phases. Ba...
Article
Full-text available
As the work of the IWA Task Group on Benchmarking of Control Strategies for WWTPs is coming towards an end, it is essential to disseminate the knowledge gained. For this reason, all authors of the IWA Scientific and Technical Report on benchmarking have come together to provide their insights, highlighting areas where knowledge may still be deficie...
Article
Full-text available
The COST/IWA Benchmark Simulation Model No 1 (BSM1) has been available for almost a decade. Its primary purpose has been to create a platform for control strategy benchmarking of activated sludge processes. The fact that the research work related to the benchmark simulation models has resulted in more than 300 publications worldwide demonstrates th...
Article
Full-text available
In this paper an extended version of IWA's Activated Sludge Model No 3 (ASM3) was developed to simulate processes in waste stabilisation ponds (WSP). The model modifications included the integration of algae biomass and gas transfer processes for oxygen, carbon dioxide and ammonia depending on wind velocity and a simple ionic equilibrium. The model...
Article
Zusammenfassung Für die Steuerung und Regelung von Kläranlagen wird in der Literatur eine unüberschaubare Anzahl von Konzepten und Varianten publiziert. Um unterschiedliche Ansätze objektiv bewerten und vergleichen zu können, wird in der hier vorgestellten Initiative ein Benchmark-System definiert, das aus einer Sammlung von Simulationskomponenten...
Article
This paper describes a method to decrease the additional measurement effort during a model calibration/verification to create reliable models for plant optimisation. The method is based on the deterministic processes creating the dry weather inflow to municipal treatment plants, which can be described by a simple influent composition model. This me...
Article
Mathematical modelling has proven to be very useful in process design, operation and optimisation. A recent trend in WWTP modelling is to include the different subunits in so-called plant-wide models rather than focusing on parts of the entire process. One example of a typical plant-wide model is the coupling of an upstream activated sludge plant (...
Article
In five full-scale municipal sequential batch reactor (SBR) wastewater treatment plants (WWTPs) indications for lag phases, a dynamic alpha factor and ammonium adsorption behaviour of the activated sludge were found. A dynamic simulation analysis of all WWTPs showed the need to implement these characteristics into the model in order to improve the...
Article
Full-text available
Integrated modelling is currently receiving a lot of attention in the field of urban hydrology. This paper describes a method for carrying out integrated modelling of sewer systems and rivers, where the constituent models are linked to each other using the European OpenMI interface. This has the advantage that, once the necessary software extension...
Conference Paper
A novel concept for a systematic design procedure of a distributed controller network for global control of a sewer network is proposed. This concept is based on two simple controller types (local throttle controller, supervisory controller) which are connected systematically based on the structure of the sewer network and the available throttle an...
Article
Full-text available
When using dynamic simulation for fine tuning of the design of activated sludge (AS) plants diurnal variations of influent data are required. For this application usually only data from the design process and no measured data are available. In this paper a simple method to generate diurnal variations of wastewater flow and concentrations is describ...
Article
A novel concept for a systematic design procedure of a distributed controller network for global control of a sewer network is proposed. This concept is based on two simple controller types (local throttle controller, supervisory controller) which are connected systematically based on the structure of the sewer network and the available throttle an...
Article
Full-text available
When assessing urban wastewater systems regarding emission-based criteria, the individual sub systems (sewer systems, wastewater treatment plant etc.) were in the past often investigated separately. Since the implementation of the EU Water Framework Directive in 2000, the authorities have switched to immission-based evaluations. To achieve this obj...
Article
Full-text available
The present document presents in details the final state of Benchmark Simulation Model no. 1 (BSM1). The model equations to be implemented for the proposed layout, the procedure to test the implementation and the performance criteria to be used are described, as well as the sensors and control handles. Finally open-loop and closed-loop results obta...
Article
Full-text available
Over a decade ago, the concept of objectively evaluating the performance of control strategies by simulating them using a standard model implementation was introduced for activated sludge wastewater treatment plants. The resulting Benchmark Simulation Model No 1 (BSM1) has been the basis for a significant new development that is reported on here: R...
Article
Full-text available
The use of goodness-of-fit measures to quantify the accuracy is controversially discussed in recent publications of modelling in the field of hydrologic and ecological research and practise. In the field of activated sludge modelling however there is neither a standard recommendation for the use of objective evaluations nor is there a discussion on...
Article
Full-text available
A model for the response time of aeration systems at WWTPs is proposed. It includes the delays caused by the air supply system (consisting of blowers, throttles and pipes), the rise time of the air bubbles and all control loops except the master DO controller. Beside a description of the required step-change experiments, different approaches for mo...
Article
In this paper, problems related to simulation model documentation and model exchange between users are discussed. Complex simulation models have gained popularity in the environmental field, but require extensive documentation to allow independent implementation. The existence of different simulation platforms puts high demands on the quality of th...
Article
Full-text available
The COST/IWA benchmark simulation model has been available for seven years. Its primary purpose has been to create a platform for control strategy benchmarking of activated sludge processes. The fact that the benchmark has resulted in more than 100 publications, not only in Europe but also worldwide, demonstrates the interest in such a tool within...
Article
Simulation techniques are well established in the fundamental research on wastewater treatment. However, there is a growing interest in using these techniques for plant design.The complexity of recent models stimulates concepts of quality assurance and model exchange.To tackle these tasks,the authors describe an approach to a formal model descripti...
Conference Paper
A fundamental pre-condition for the application of simulation is the availability of reliable models. Particular problems arise in the application of simulation for integrated process design of complex wastewater systems. The models necessary for this task have to include different sub-processes such as biological wastewater treatment, anaerobic di...
Article
This paper presents a generic procedure for the development of real time control (RTC) algorithms for urban drainage systems. Essentially RTC control actions are expressed as a function of known input variables (e.g. water level measurements). Using a simulation model, the procedure is tested on an example and shows to be successful in finding a go...
Article
Besides the treatment efficiency for WWTPs, recent efforts focus on reduction of operational costs, especially the energy consumption which is closely connected with sludge treatment. A proven approach to improve plant performance is the application of tailor made control concepts developed frequently using dynamic simulation models. A set of appro...
Conference Paper
Full-text available
The paper discusses about the wastewater process modelling in Simulink and SIMBA process library. The paper presents the discussion of dynamic simulation - motivation, the models of the activated sludge process and the simulation system for wastewater process.
Article
Full-text available
A guideline for simulation studies of wastewater treatment plants is proposed. The aim of the HSG-guideline is to define a reference quality level that helps to make the results of simulation studies comprehensible and comparable and therefore increases the quality and reliability of mathematical modelling in wastewater treatment. The paper gives a...
Article
Full-text available
To ensure correctly operating control systems, the measurement and control equipment in WWTPs must be mutually consistent. The dynamic simulation of activated sludge systems could offer a suitable tool for designing and optimising control strategies. Ideal or simplified sensor models represent a limiting factor for comparability with field applicat...